|Title||Cardiac drift during prolonged exercise with echocardiographic evidence of reduced diastolic function of the heart|
|Authors||Dawson, E. A., Shave, R., George, K., Whyte, G., Ball, D., Gaze, D.C. and Collinson, P.O.|
This study examined whether, in 16 male subjects, a continuous increase in heart rate (HR) during 4 h of ergometry cycling relates to cardiac fatigue or cardiomyocyte damage. Serum cardiac troponin T (cTnT) was determined and echocardiographic assessment was carried out prior to and after 2 h of exercise, within 15 min of completing exercise and after 24 h. Left ventricular contractile function (end-systolic blood pressure–volume relationship [SBP/ESV]) and diastolic filling (ratio of early to late peak left ventricular filling velocities [E:A]) were calculated. During exercise HR was 132±5 beats min−1 after 2 h and increased to 141±5 beats min−1 (mean ± SD; P<0.05), but there was no evidence of altered LV contractile function (SBP/ESV 39.0±5.1 mmHg cm−1 to 36.5±5.2 mmHg cm−1 and SBP/ESV was not correlated to maximal oxygen uptake (r2=0.363). In contrast, E:A decreased (1.82±0.32 to 1.48±0.30; P<0.05) and returned towards baseline after 24 h (1.78±0.28), and individual changes were correlated to maximal oxygen uptake (r2=0.61; P<0.05). Low levels of cTnT were detected in two subjects after 4 h of exercise that had normalised by 24 h of recovery. During prolonged exercise cardiovascular drift occurred with echocardiographic signs of a reduced diastolic function of the heart, especially in those subjects with a high maximal oxygen uptake.
|Keywords||Echocardiography, Cardiac troponin T|
|Journal||European Journal of Applied Physiology|
|Journal citation||94, pp. 305-309|
|Digital Object Identifier (DOI)||https://doi.org/10.1007/s00421-005-1318-3|
|Published||12 Mar 2005|